package Year21_Month10.day1030;


import java.util.Scanner;

public class Main{
        public static void main(String[] args){
            Scanner sc = new Scanner(System.in);
            while(sc.hasNext()){
                String s = sc.next();
                fac(s);
            }

        }

        public static void fac(String s){
            char[] array = s.toCharArray();
            int i = 0;//用来遍历数组
            while(i < array.length && array[i] != ' '){
                for(int j = i + 1;j < array.length;j++){
                    if(array[i] == array[j]){
                        array[j] = ' ';
                    }
                }
                i++;
            }
            for(i = 0;i < array.length;i++){
                if(array[i] != ' '){
                    System.out.print(array[i]);
                }
            }
        }
    }
